Method and apparatus for realizing local id allocation for ue-to-ue relay communication in a wireless communication system

Abstract

A method and device are disclosed for supporting a third User Equipment (UE). In one embodiment, the third UE receives a first PC5-S message from a first UE for initiating a procedure of establishing a first layer-2 link between the first UE and the third UE. The third UE also transmits a second PC5-S message to the first UE for establishing a first security context between the first UE and the third UE in the procedure of establishing the first layer-2 link. The third UE further receives a third PC5-S message from the first UE for completing establishment of the first security context in the procedure of establishing the first layer-2 link. In addition, the third UE transmits a fourth PC5-S message to the first UE for completing the procedure of establishing the first layer-2 link, wherein the fourth PC5-S message includes a layer-2 identity of a second UE.

1 . A method for a third User Equipment (UE), comprising:
 the third UE receives a first PC5-S message from a first UE for initiating a procedure of establishing a first layer-2 link between the first UE and the third UE;   the third UE transmits a second PC5-S message to the first UE for establishing a first security context between the first UE and the third UE in the procedure of establishing the first layer-2 link;   the third UE receives a third PC5-S message from the first UE for completing establishment of the first security context in the procedure of establishing the first layer-2 link; and   the third UE transmits a fourth PC5-S message to the first UE for completing the procedure of establishing the first layer-2 link, wherein the fourth PC5-S message includes a layer-2 identity (L2ID) of a second UE.   
     
     
         2 . The method of  claim 1 , comprising:
 the third UE, in response to reception of the first PC5-S message, transmits a fifth PC5-S message to the second UE for initiating a procedure of establishing a second layer-2 link between the second UE and the third UE; and   the third UE receives a sixth PC5-S message from the second UE for establishing a second security context between the second UE and the third UE in the procedure of establishing the second layer-2 link.   
     
     
         3 . The method of  claim 2 , wherein the first PC5-S message contains an upper layer identity or an application layer identity of the second UE, and/or the sixth PC5-S message is received by using a L2ID of the third UE as Destination L2ID and the L2ID of the second UE as Source L2ID. 
     
     
         4 . The method of  claim 1 , wherein the first UE is a source remote UE, the second UE is a target remote UE and the third UE is a UE-to-UE relay UE. 
     
     
         5 . A third User Equipment (UE), comprising:
 a control circuit;   a processor installed in the control circuit; and   a memory installed in the control circuit and operatively coupled to the processor;   wherein the processor is configured to execute a program code stored in the memory to:
 receive a first PC5-S message from a first UE for initiating a procedure of establishing a first layer-2 link between the first UE and the third UE; 
 transmit a second PC5-S message to the first UE for establishing a first security context between the first UE and the third UE in the procedure of establishing the first layer-2 link; 
 receive a third PC5-S message from the first UE for completing establishment of the first security context in the procedure of establishing the first layer-2 link; and 
 transmit a fourth PC5-S message to the first UE for completing the procedure of establishing the first layer-2 link, wherein the fourth PC5-S message includes a layer-2 identity (L2ID) of a second UE. 
   
     
     
         6 . The third UE of  claim 5 , wherein the processor is further configured to execute a program code stored in the memory to:
 transmit, in response to reception of the first PC5-S message, a fifth PC5-S message to the second UE for initiating a procedure of establishing a second layer-2 link between the second UE and the third UE; and   receive a sixth PC5-S message from the second UE for establishing a second security context between the second UE and the third UE in the procedure of establishing the second layer-2 link.   
     
     
         7 . The third UE of  claim 6 , wherein the first PC5-S message contains an upper layer identity or an application layer identity of the second UE, and/or the sixth PC5-S message is received by using a L2ID of the third UE as Destination L2ID and the L2ID of the second UE as Source L2ID. 
     
     
         8 . The third UE of  claim 5 , wherein the first UE is a source remote UE, the second UE is a target remote UE and the third UE is a UE-to-UE relay UE. 
     
     
         9 . A method for a third User Equipment (UE), comprising:
 the third UE receives a first PC5-S message from a first UE for initiating a procedure of establishing a first layer-2 link between the first UE and the third UE; and   the third UE, in response to reception of the first PC5-S message, initiates a procedure of establishing a second layer-2 link between a second UE and the third UE, wherein the third UE sends a layer-2 identity (L2ID) of the first UE to the second UE in the procedure of establishing the second layer-2 link.   
     
     
         10 . The method of  claim 9 , comprising:
 the third UE transmits a second PC5-S message to the second UE for request of establishing the second layer-2 link in the procedure of establishing the second layer-2 link;   the third UE receives a third PC5-S message from the second UE for establishing a second security context between the second UE and the third UE in the procedure of establishing the second layer-2 link;   the third UE transmits a fourth PC5-S message to the second UE for completing establishment of the second security context in the procedure of establishing the second layer-2 link; and   the third UE receives a fifth PC5-S message from the second UE for completing the procedure of establishing the second layer-2 link.   
     
     
         11 . The method of  claim 10 , wherein the first PC5-S message contains an upper layer identity or an application layer identity of the second UE, the first PC5-S message is received by using a first L2ID of the third UE as Destination L2ID and the L2ID of the first UE as Source L2ID, and/or the second PC5-S message is sent by using a L2ID of the third UE as Source L2ID and a L2ID of the second UE or a common address as Destination L2ID. 
     
     
         12 . The method of  claim 10 , wherein the L2ID of the first UE is included in the second PC5-S message or the fourth PC5-S message. 
     
     
         13 . The method of  claim 9 , wherein the first UE is a source remote UE, the second UE is a target remote UE and the third UE is a UE-to-UE relay UE. 
     
     
         14 . A third User Equipment (UE), comprising:
 a control circuit;   a processor installed in the control circuit; and   a memory installed in the control circuit and operatively coupled to the processor;   wherein the processor is configured to execute a program code stored in the memory to:
 receive a first PC5-S message from a first UE for initiating a procedure of establishing a first layer-2 link between the first UE and the third UE; and 
 initiate, in response to reception of the first PC5-S message, a procedure of establishing a second layer-2 link between a second UE and the third UE, wherein the third UE sends a layer-2 identity (L2ID) of the first UE to the second UE in the procedure of establishing the second layer-2 link. 
   
     
     
         15 . The third UE of  claim 14 , wherein the processor is further configured to execute a program code stored in the memory to:
 transmit a second PC5-S message to the second UE for request of establishing the second layer-2 link in the procedure of establishing the second layer-2 link;   receive a third PC5-S message from the second UE for establishing a second security context between the second UE and the third UE in the procedure of establishing the second layer-2 link;   transmit a fourth PC5-S message to the second UE for completing establishment of the second security context in the procedure of establishing the second layer-2 link; and   receive a fifth PC5-S message from the second UE for completing the procedure of establishing the second layer-2 link.   
     
     
         16 . The third UE of  claim 15 , wherein the first PC5-S message contains an upper layer identity or an application layer identity of the second UE, the first PC5-S message is received by using a first L2ID of the third UE as Destination L2ID and the L2ID of the first UE as Source L2ID, and/or the second PC5-S message is sent by using a L2ID of the third UE as Source L2ID and a L2ID of the second UE or a common address as Destination L2ID. 
     
     
         17 . The third UE of  claim 15 , wherein the L2ID of the first UE is included in the second PC5-S message or the fourth PC5-S message. 
     
     
         18 . The third UE of  claim 14 , wherein the first UE is a source remote UE, the second UE is a target remote UE and the third UE is a UE-to-UE relay UE.